In an effort to develop better knowledge of factors that affect X-ray utilization in the current health care system, we propose to examine the role of administrative X-rays as a significant component of total utilization. The investigation will focus on the chest and lumbar spine X-ray procedures and will involve a component which measures use of these procedures and a component which examines the policies surrounding their use. In the use component, we will use a statewide sample of corporations and third-party carrier data to estimate: the frequency or volume of these procedures; the total dollar cost involved in their use; the characteristics of the population subject to the procedure; and, exposure and dose levels associated with administrative chest and lumbar spine X-rays. In the policy component, we propose to use interviews and document review to examine the perceptions of X-ray yield and policy within levels of single organizations and between organizations which do and do not use administrative X-rays. The investigation will focus on legislated, negotiated, and corporate X-ray policy. Our objective is to obtain a comprehensive list of expected outcomes of the X-ray procedures, an accurate description of the mechanisms which relate these outcomes to utility, and an impression of the sequence of changes to which these outcomes and policies have been subjected in recent years. We hope to provide general recommendations regarding leverage points for better utilization.